|“||Unfortunately, I'm no ordinary human.||”|
Sakae has golden hair and eyes, though it is unknown as to whether his colouring came through the use of dye and contacts.
His hair was of medium-length, reaching the nape of his neck and was either loose or half-up. He is commonly seen in a school uniform.
From his appearances thus far, Sakae is shown to mutter frequently, and have a somnolent, indifferent character.
He was noted for having acted oddly, such as secretly nodding or talking to himself which Hanae takes as Sakae conversing with Yōkai.
He also seems to care and worry for Hanae, possessing him in order to save him, saying, "at this rate, you'll be killed too."
According to Haruitsuki's research into Aoi's records and the recounts of the Mononokean, there was an incident 16 years ago. Aoi-sama came back injured after disappearing for many hours for a job. When the Mononokean scroll questioned what had happened, Aoi responded "I watched a cat die", then they wept. Haruitsuki guesses the cat refers to Sakae, as he was secretly employed with Aoi since he was human, and so in Aoi's records they inserted Sakae as a metaphor, being a cat. It is the revealed that for some unknown reason, three years later, Aoi-sama disguised himself as Sakae and went to visit the Ashiya family on Christmas eve and left a doodled heart in their records for that day.
Nara Ashiya mentions Sakae after Hanae pulls a yōkai that possesses her, causing her to fall ill. Nara states she would always instantly feel better once Sakae comes around and does the same thing Hanae just did. Nara then claims Hanae takes up after his father in a weird way.
One snowy Christmas Eve, a young Hanae meets a man wearing a cloak and asks him if he is Santa. The man says no then picks Hanae up and embraces him. The man states Santa asked him to come see Hanae. In response, Hanae asks if the man is his father. The man says yes and tells him it is nice meeting him. The man was later revealed to be Aoi in disguise.
Hanae questions his sister whether their father ever told her he can see yōkai or whether she witnessed him acting strange. Hanae is cut off by his sister, whose usual cheery attitude is replaced by anger, and states that she doesn't want to talk about a man who abandoned his family. After a few moments, Hanae's sister apologizes for her earlier behavior and answers Hanae's question that their father has never mentioned seeing yōkai or anything strange but notes that it was strange that their mother would always get better if he goes near her when she isn't feeling well. She further adds that on those days, Sakae would act oddly, look around a lot and secretly talk or nod to himself. Hanae takes this as a proof his father was able to see yōkai, too.
When Hanae was controlled by Sasa and thought that he has killed Haruitsuki, Sakae appears in Hanae's subconscious. He tells Hanae that at the rate Hanae is going with his powers, he will be killed, too. He possesses Hanae's body. Sasa pushingly orders Hanae to kill Haruitsuki. Sakae, now inside Hanae's body responds and orders the yōkai to shut up and states he doesn't need to shout as he can hear him. Sakae mutters about how a mere yōkai orders him around and tells the yōkai to kill Haruitsuki himself if he wants it that badly. Sakae breaks the seal of the shrine Sasa is kept in. Sakae asks the yōkai if he's not coming out after opening his prison. The yōkai notes the change in Hanae's eyes, which has turned into the color of Sakae's eyes, gold, due to possession. Outraged, the yōkai asks why does an ordinary human has eyes of that color. Sakae responds that unfortunately, he is no ordinary human and that he can exorcise yōkai. Sakae then uses his Influence and orders Sasa to "disappear".
As Sasa starts screaming that he doesn't want to disappear, a memory of his meeting with Sakae was shown, in which Sasa begs Sakae to spare his life, but Sakae, deeming him untrustworthy, seals Sasa inside the shrine.
After Sasa disappears, Sakae starts to fall asleep, losing his hold on Hanae, but Haruitsuki orders him to stay up and says that he has two things to ask. Sakae tells him to hurry since he is already at his limits, so Haruitsuki asks if the one who sealed Sasa was him. He replies vaguely that he doesn't remember, but says if that's what Abeno says, then it must be so as not many humans can do it. He then appears to lose consciousness, but asks "what the other thing is?" Haruitsuki just thanks him for saving Hanae as Sakae falls asleep.
- Though he has exorcised numerous yokai with his influence, he never tried sealing until he decided to test it on Sasa.
- Sakae was symbolised as a cat during his time of employment to the Mononokean.
- "You don't need to shout. I can hear you..."
- "If you want to kill him so badly, come out and do it yourself..."